I'll start by saying that I feel ridiculous and defeated. Note: Jump to the bottom if you don't care about the story.
I went to a local bike swap today to get a new helmet or at least see what was there. In the end I determined that buying a used helmet would be stupid but not before I determined that I needed new brakes for my late 80s road bike. I should mention that I've never had any problems stopping on my current set up, so it makes this all the more humiliating. I asked a mechanic at the shop if brakes were universal and he told me that they were for the most part. I don't have an unusual bike, so I got a set of Ultegras for $25 and an obnoxious yellow Tinker Juarez saddle because it was $3 (how can you pass that up). I set off home to install my new brakes. Several hours and a few beers later, I am the proud owner of a late 80s road bike with no brakes and an obnoxious yellow Tinker Juarez saddle. It seemed easy enough...just take the old ones off and put the new ones on. Not so fast. Here are the details.
The Problem (bear with me as my terminology is no good):
The old Dia Compe sidepull brakes have a longer pivot bolt "stem" (the threaded bolt that goes through to the other side of the fork). When I went to put on the new brakes which are dual pivot, the stem wasn't long enough to get the "hex nut" onto the threads of that bolt. I don't know if I'm thinking inside a box or if the brakes simply aren't compatible with my frame. Any insight would be great. Thanks in advance!
Frame: I think it's a giant frame, but badged as "Sanwa" again, mid/late 80s maybe.
Current Brakes: Dia Compe N500 http://http://www.velobase.com/ViewS...0-5225c19ab65a
New Brakes: Shimano Ultegra BR-6500 http://http://www.roadbikereview.com...0_2480crx.aspx